.footer {
    font-size: 12px;
    color: #999;
    width: 100%;
    height: 70px;
    font-family: MicrosoftYaHei-Bold, Microsoft YaHei, verdana, heiti;
    background: #fff;
    line-height: 70px;
    margin-top: 168px;
    text-align: center;
    border-top: 1px solid #ccc;
}

.back-to-top {
    display: none;
    font-size: 14px;
    position: fixed;
    left: 50%;
    bottom: 260px;
    margin-left: 650px;
    width: 15px;
    line-height: 1.2;
}

.back-to-top a {
    color: #333;
    display: block;
    padding: 0 10px;
}

.back-to-top .icon-chevron-up {
    margin-left: 1px;
    margin-bottom: -4px;
    display: inline-block;
    border-top: 3px solid #000000;
    border-left: 3px solid #000000;
    width: 8px;
    height: 8px;
    transform: rotate(45deg);
    -ms-transform: rotate(45deg); /* IE 9 */
    -moz-transform: rotate(45deg); /* Firefox */
    -webkit-transform: rotate(45deg); /* Safari 和 Chrome */
    -o-transform: rotate(45deg);
}
